The sighting was reported to police by NSW Ambulance officers on a helicopter training exercise at around 4pm (AEST) on Monday.
Police attached to the Blue Mountains Local Area Command will launch a retrieval operation to the site on Tuesday, as it is inaccessible by foot.
The sighting comes after Mr Tweddle went missing from a work conference at Leura resort in mid-July.
“It’s very likely it is Gary but we will have to wait and see,” Blue Mountains crime manager Mick Bostock told Blue Mountains Gazette.
“Earlier this afternoon an ambulance helicopter was involved in a training exercise near bushland at Leura in a remote area where there is a rock climb known Sweet Dreams. They have located what appears to be a body.”
Sales rep Gary Tweddle who went missing in the Blue Mountains near Sydney (image via Facebook)
He had called colleagues about midnight to tell them he was lost in bushland but could see a light up a hill. Ten days after the 23-year-old disappeared, the search for him was scaled back to a recovery operation.
“Over the past 10 days more than 1000 people have searched, co-ordinated and supported the efforts to locate and return Gary safely,” Mr Tweddle’s father David said in his Facebook post on July 25.
“Most of these people are volunteers with lives and jobs, yet they did 10 days on the bounce. A massive thank you to them, their families and their employers. What can I say? Amazing,” he wrote.
Image via Thinkstock